在Random Walk Simulation的R代码中（for（t in 2：1000））的含义是什么？

Question

for（t in 2：1000）是什么意思？

x = e = rnorm(1000)
for (t in 2:1000) x[t] = x[t-1] + e[t]
windows()
plot(x, type="l")
acf(x)
acf(diff(x))

Answer 1

试试看：

for (t in 2:20) { x[t] = x[t-1] + e[t]
print(t)}

[1] 2
[1] 3
[1] 4
[1] 5
[1] 6
[1] 7
[1] 8
[1] 9
[1] 10
[1] 11
[1] 12
[1] 13
[1] 14
[1] 15
[1] 16
[1] 17
[1] 18
[1] 19
[1] 20